why my captive portal on ise 1.2 asks users to autenticate two times before grant the access?

[Giuseppe Trig]

Why my guest users need to authenticate two times before access internet?

I use ISE 1.2

[Saurav Lodh]

Is the below been configured for guest role?

Guest Users must first sign into through the Guest captive portal before they will be able to access other parts of the network (such as with Central Web Authentication (CWA)).

[Giuseppe Trig]

yes, users are configured as guest.

They access to the guest network and the ISE captive portal appears asking for user and password.

Users put the username and password and flag the policy. The portal says the they now can surf the internet but as soon as they type an address the captive portal come back asking again for user and password.

If users type again the same password they now can surf without any kind of problem.

This happens every time a user access the guest wifi for the first time.